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M. CORYELL. COMPOUND STEAM ENGINE.

No. 400-,641.. Patented Apr. 2, 1889..

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ZISheets-Sheet 2.

(No Model.)

OORYELL. COMPOUND STEAM ENGINE.

Patented Apr. 2, 1889.

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UNITED STATES PATE T OFFICE.

MIERS CORYELL, OF NEIV YORK, N. Y.

COMPOUND STEAM-ENGINE.

SPECIFICATION formingpart of Letters Patent No. 400,641, dated April 2, 1889.

Application filed July 28, 1888.

To all whonti may concern:

Be it known that I, MIERs CORYELL, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain Improvements in Compound Steam-Engines, of which the following is a specification.

My invention relates to multiple-cylinder engines, and particularly to compound highpressure high-speedsteam-engines; and my object is in part to effect an important economy in the construction, and in part to reduce the inertia of the moving parts to a minimum, and thus to effect both'a static and rotative balance of these parts.

My invention will be fully described hereinafter, and its novel features carefully defined in the claims.

In the drawings which serve to illustrate my invention, I have shown it embodied in both a vertical and a horizontal engine; and I will say that while I prefer to employ it in a vertical engine with the shaftabove the cylinders, the same patterns may be employed almost throughout, whatever may be the type of engine required.

Figure 1 is a side elevation of a vertical compound engine embodying my improvements, the main shaft being arranged above the cylinders, and Fig. 2 is a plan of the same. Fig. 3 is a side elevation of a similar engine embodying my improvements, in which the axes of the cylinders are horizontal. Fig. 4 is a View of the tie-plate E detached; and Fig. 5 is atransverse section through said tieplate, showing the manner of mounting the rock-shaft therein. Fig. 6 is a transverse horizontal section on line 6 6 in Fig. 1. Fig. 7 is a horizontal section of the cylinders and valve-chambers.

In describing my invention I will first refer to Figs. 1, 2, 4., 5, 6, and 7.

A is a bed-plate, on which are mounted two columns, B B, in which are provided bearings for the journals on the main or crank shaft 0. In Fig. 2 one of these columns is broken away in order to show the mechanism below. D is the high-pressure cylinder, and D is the low-pressure cylinder; These cylinders are cast in one piece and bolted down firmly on the bed-plate.

On the tie-piece or part of the casting be- Serial No. 281,292. (No model.)

tween the cylinders is mounted a tie-plate or frame, E, which is bolted down firmly at its foot, and secured at its upper end between and to the columns B B. This frame E is shown detached in Fig. 4. At its upper end it has a tubular part, e,'which fits between the cheeks on the columns B, and the bore therein coincides or registers with holes in the said cheeks. A rod, 6', is passed through the three parts, and nuts 6 on the ends of the rod serve to secure the upper end of plate E to the columns.

F is the piston-rod of the high-pressure cylinder. This rod is provided with a crosshead, f, which plays on a guide, f, secured to the face of the plate E. The rod F is coupled to the crank c of the main shaft 0 by a connecting-rod, G.

H is the piston-rod of the low-pressure cylinder. This rod is provided with a cross-head, h, which plays on a guide, it, secured to the other face of the plate E. The piston-rod H is coupled by a rod, 71 to one end of a rocking beam, I, mounted in bearings at z in the columns B, .over plate E, and the other end of this beam is coupled by a pair of rods or links, j, to the cross-head f of the high-pressure cylinder D. The result of this construction is that the pistons in the cylinders D and D move simultaneously in opposite directions.

J is the steam-chest or the valve-chamber of the high-pressure cylinder D, and J is the valve-chamber on the low-pressure cylinder D. Each cylinder is provided with slidevalves of the usual form, which have each a cut-off valve, also of the usual form, mounted on its back. These being well-known constructions, I have not deemed it necessary to illustrate them.

In suitable bearings in tie-plate E is mounted a rock-shaft, k, (seen best in Fig. 5,) on one end of which is secured an operating-arm, k. This arm is coupled by a rod, 10 to the strap of a cut-off eccentric, l, on the main shaft C On the other end of the rook-shaft 7c are two oppositely-projecting valve-operating arms, m m, the former of which is coupled to the stem 91 of the cut-off valve of the highpressure cylinder, and the latter to the stem n of the cut-off valve of the low-pressure cylinder.

On the shaft 70, as a journal, is mounted a rocking lever, one arm, 0, of which is coupled to the strap of the eccentric Z, which actuates the main valves. The arms 0 and 0 of this rocking lever are coupled, respectively, to the stems r and r of the main valves of the high and low pressure cylinders. This construction provides a simple, durable, and inexpensive valve-gear, whereby the steam is worked expansively in both cylinders. The steam from the generator enters the valve chamber or chest J of the high-pressure cylinder at the inlet 00, and when exhausted from this cylinder it enters a receiving-chamber, s, (seen in Fig. 7,) formed in the tie-piece which unites the high and low pressure cylinders. This chambers connects with the valve chamber or chest J of the low-pressure cylinder, and the latter cylinder is thus supplied with steam from the hi gh-pressure-cylinder exhaust. The steam exhausted from the low-pressure cylinder enters a jacket-like chamber, 8, from which it eventually escapes at the exhaustoutlet y. The chambers s and s serve as jackets for the low-pressure cylinder, and prevent undue radiation of the heat therefrom. These chambers are very conveniently formed by coring out the casting of which the two cylinders and their tie-piece are integrally formed; but this integral construction is not essential.

It will be understood that both cylinders are double-acting, and for a high-speed engine they will have short strokes, as represented herein.

Fig. 3 illustrates the embodiment of my invention in a horizontal steam-engine. In this construction the positions of the cylinders D and D are reversed in order to superimpose the lesser cylinder; but the cross-heads, connecting-rods, the, remain as in Fig. 1, and to avoid confusion in comparing the figures the letters of reference on these parts are arranged the same as in Fig. 1, notwithstanding the reversal of the arrangement of the cylinders. Indeed, the cylinders need not be reversed.

In Fig. 3 the pillars B B are arranged horizontally as a bed-plate, the upper cylinders being stayed by branches B on said pillars, extending back and secured to the cylinder.

An engine of the form shown in Fig. 1 may be inverted, the only alteration required being a suitable modification of the bed-plate and pillars or columns. The weight of the moving parts on one side of the pivotal axis of the rocking beam I is substantially the same as that on the other side, and thus a balance of the parts is effected.

The pillars B B of the upright engine (illustrated in Figs. 1 and 2) are arched or curved in such a manner as to effect two objectsnamely, to give free access to the valve-chests and to place the main shaft C, which carries the fly-wheel, over a point about midway between the bases of the pillars and the base of the tie-plate E. This imparts steadiness to the structure.

The arms 0 and m, that actuate the valves of the low-pressure cylinder, are a little longer than those that actuate the valves of the highpressure cylinder, and thusa little more play is imparted to the former than to the latter.

It will be seen that the tie-plate E plays a very important part in my engine. It supports the rocking beam I and the rock-shaft lo, and provides a support also for the crosshead guides. The overhanging ends of the pillars B B are tied together, supported, and tied to the cylinders, also, by said tie-plate.

The same principles of construction I have shown herein may be applied to compound engines with more than two cylinders.

Having thus described my invention, I claim- 1. In a compound engine wherein the steam is worked expansively in all the cylinders, the valve-operating mechanism comprising the rock-shaft 70, having an arm, coupled to the eccentric which actuates the cut-01f valves, and two oppositely-arranged arms, m and m, coupled to the respective stems of the cut-oft valves, and a rocking lever mounted on shaft Zr, and having its arms 0 and 0' coupled, respectively, to the stems of the main valves, the arms 0 being also coupled to the eccentric which actuates the main valves, as set forth.

2. The combination, with the bed-plate, the pillars, and the cylinders, of the tie-plate E, mounted on and secured to the cylinders, and connected to the pillars at its upper end, said tie-plate having a tubular part, c, to receive a tie-rod, e',the said rod, and the nuts 6 substantially as and for the purposes set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

MIERS CORYELL. itnesses:

HENRY CONNETT, J. D. CAPLINGER. 

